Publications by authors named "J Duhamel"
Article Synopsis
- The primate posterior parietal cortex (PPC) processes visual space for navigation, while the hippocampus (HPC) creates a memory-based map of the environment.
- A study of macaques navigating a virtual maze revealed that neurons in both PPC and HPC showed spatial selectivity, indicating a link between visual cues and self-positioning.
- Key neuron populations, responsive to saccades and fixations, contributed to navigation tasks, and both regions even anticipated landmarks before they became visible, suggesting a shared understanding of spatial layout.
Article Synopsis
- The study investigates the dimerization of oligoquinoline foldamers (OPV-QA) that have different lengths, focusing on how they interact in a chloroform solution when mixed with a strong sodium hydroxide solution.
- Using UV-vis absorption and time-resolved fluorescence anisotropy (TRFA), the researchers measured the concentration and rotational time of both associated and unassociated foldamers, finding that the association increased with the foldamer concentration during vigorous mixing.
- Results showed that at higher concentrations, the foldamers formed larger structures through metal coordination, and the dimerization was quantified with equilibrium constants, indicating that longer foldamers had a stronger tendency to dimerize compared to the shortest one.
A series of poly(alkyl methacrylate)s and poly(oligo(ethylene glycol) methyl ether methacrylate)s labeled with 1-pyrenebutanol were referred to as the PyC-PCMA samples with = 1, 4, 6, 8, 12, and 18 and the PyC-PEGMA samples with = 0-5, 9, 16, and 19, respectively. Pyrene excimer formation (PEF) upon the encounter between an excited and a ground-state pyrenyl labels was employed to determine their persistence length () in -xylene. The fluorescence decays of the PyC-PCMA and PyC-PEGMA samples were acquired and analyzed with the fluorescence blob model to yield the number () of structural units in the volume probed by an excited pyrenyl label.
View Article and Find Full Text PDFAllogrooming is a widespread, pervasive activity among non-human primates. Besides its hygienic function, it is thought to be instrumental in maintaining social bonds and establishing hierarchical structures within groups. However, the question arises as to whether the physiological and social benefits derived from social touch stem directly from body stimulation, or whether other mechanisms come into play.
View Article and Find Full Text PDFSize exclusion chromatography (SEC) and pyrene excimer formation (PEF) experiments were conducted to characterize the local density profile inside a glycogen sample before (Glycogen) and after (Gly-β-LD) treatment with β-amylase. These experiments were conducted to assess whether the density at the periphery of the glycogen particles was very high to limit access to proteins involved in the metabolism of glycogen as predicted by the Tier model or low as suggested by the Gilbert model. SEC analysis indicated that the density inside the Glycogen and Gly-β-LD samples remained constant with particle size and was not affected by β-amylolysis.
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